Actually, Raggy, I have just twigged.

If you agree with Dave that it is objectionable, then I was right.
If you agree with me that it is not, then I do owe you an apology.

Just agree that the festival is not objectionable and Keith will owe you an apology. I also agree that the festival is not objectionable so it is a win/win situation.

I bet he doesn't apologise though ;-)